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This frequency table shows the results o...

This frequency table shows the results of a small class quiz . If a student is selected at random, the probability that he or she scored 2, 4, or 5 is
`{:("Marks ", "Frequency "),(" "1," "4),(" "2," "3),(" "3," "2),(" "4," "6),(" "5," "5):}`

A

`(3)/(20)`

B

`(1)/(4)`

C

`(7)/(10)`

D

`(9)/(20)`

Text Solution

AI Generated Solution

The correct Answer is:
To find the probability that a randomly selected student scored 2, 4, or 5 marks, we will follow these steps: ### Step 1: Calculate the total number of students We need to sum the frequencies of all scores given in the frequency table. - Frequency of students who scored 1: 4 - Frequency of students who scored 2: 3 - Frequency of students who scored 3: 2 - Frequency of students who scored 4: 6 - Frequency of students who scored 5: 5 Total number of students = 4 + 3 + 2 + 6 + 5 **Calculation:** - 4 + 3 = 7 - 7 + 2 = 9 - 9 + 6 = 15 - 15 + 5 = 20 **Total number of students = 20** ### Step 2: Calculate the number of favorable outcomes Next, we need to find out how many students scored either 2, 4, or 5 marks. - Students who scored 2: 3 - Students who scored 4: 6 - Students who scored 5: 5 Total number of students who scored 2, 4, or 5 = 3 + 6 + 5 **Calculation:** - 3 + 6 = 9 - 9 + 5 = 14 **Total number of favorable outcomes = 14** ### Step 3: Calculate the probability The probability \( P \) that a student scored 2, 4, or 5 is given by the formula: \[ P(\text{scoring 2, 4, or 5}) = \frac{\text{Number of favorable outcomes}}{\text{Total number of students}} \] Substituting the values we found: \[ P(\text{scoring 2, 4, or 5}) = \frac{14}{20} \] ### Step 4: Simplify the fraction Now we simplify the fraction \( \frac{14}{20} \). Both the numerator and the denominator can be divided by 2: \[ \frac{14 \div 2}{20 \div 2} = \frac{7}{10} \] ### Final Answer The probability that a randomly selected student scored 2, 4, or 5 is \( \frac{7}{10} \). ---
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